The MX/Alliance T1 is configured for Foreign Exchange Station (FXS)
loopstart and Super Frame (SF)/Alternate Mark Inversion (AMI). When the T1
controller on the Cisco 2851 Integrated Services Router is configured for
Foreign Exchange Office (FXO) loopstart and SF/AMI, calls from the IP phone to
the turret work fine. But the 2851 never sees an incoming seizure from the
MX/Alliance due to non-standard signaling used by the MX/Alliance.

The solution is to insert an RAD Vmux 2100 Circuit Emulator/Transport
Device between the Cisco IOS Gateway T1 Controller and the MX/Alliance Turret
System. Because the Vmux 2100 converts time-division multiplex (TDM)-to-IP and
back to TDM, the Cisco IOS Gateway T1 Controller can be configured for E&M
Immediate-Start, ESF/B8Zs while the MZ/Alliance remains configured as T1 FXS
loopstart, SF/AMI.

Complete these steps:

Connect the Vmux 2100 to the Cisco IOS Gateway T1 Controller and
the MX/Alliance Turret System according to the instructions provided by the
manufacturer.